This invention pertains to the field of food processing and in particular to cheese processing. One aspect of the invention relates to a method of manufacturing cheese to lower the amount of fat that remains in the cheese. More specifically, this aspect of the invention relates to a method of breaking the natural emulsion of cheese to release the fat from the cheese matrix, and allow for reduction of the amount of fat in the cheese. In another aspect, the invention also allows for the removal of undesirable flavors in cheese.
Consumers enjoy cheeses of all types, but would prefer cheese that has less fat than cheese made by present food-processing techniques. Cheese may be made from whole milk, generally bovine milk having 3-4% milk fat. Cheese may also be made from skim milk, that is, milk from which essentially all the fat has been removed and which has about 0.5% fat or less. Part-skim milk is also used, part-skim milk being milk from which part of the fat has been removed, resulting in milk with 1-2% milk fat. The cheese that is made from milk has a large percentage of fat, typically in the range of 20-40 percent fat. The balance of the cheese is largely moisture (40-50 percent), protein (20-30 percent), and other ingredients that are typically not more than a few percent. Cheese made by an ultrafiltration process may also have more fat than consumers wish.
In order to reduce the fat in cheese, manufacturers typically use milk with less fat as a starting material. Standard cheese processing techniques are thereafter used. A culture is added to the milk, the culture producing lactic acid from the natural lactose in milk. An enzyme may later be added, causing coagulation of the milk. Other ingredients may also be added. Coagulated milk is cut into small pieces or curd at a temperature of about 90xc2x0 F. After cutting, the curd is allowed to xe2x80x9cheal,xe2x80x9d or form a film on the surface of the pieces of curd. During this time, the curd particles start to shrink and expel whey. The curd and whey mixture is stirred and heated or cooked until a desired acidity and temperature is reached. The whey is then drained from the curd. After whey removal, the curd may be processed as desired for different types of cheese while additional lactic acid is produced by continued fermentation of the lactose. The curd may or may not be washed with water. Different cheeses are then processed as desired, including reaching the desired level of acidity, adding salt, pressing the curd into desired form, and packaging. Cheese made by this process, or by other processes, and from which a portion of the fat has not been removed, is referred to in this application as a full-fat cheese.
Part-skim milk or skim milk is used in making cheese having xe2x80x9creduced fatxe2x80x9d (at least 25% less fat than standard cheese), or xe2x80x9clightxe2x80x9d cheese (at least 50% less fat than standard), or xe2x80x9clow-fatxe2x80x9d cheese (having less than 3 grams fat per 50 gram serving), definitions according to 21 C.F.R. Sections 101.9 and 161.62, and 21 C.F.R. Section 133. However, when skim milk or part-skim milk is used to make cheese, the resulting cheese may have an undesirable rubbery texture, rather than a firm but pliable texture. The cheese may also have a variety of off-flavors, ranging from bitter to metallic to flat. Processes using skim or part-skim milk also tend to have lower yield. This results in higher cost to the cheese maker and to the consumer. Cheese makers prefer not to make lower fat cheese because the lower yield, higher cost, and poorer quality are economic disincentives. What is needed is a better way to make cheese with reduced fat content.
The present invention provides a method of making cheese with a lowered fat content that overcomes the foregoing problems. One embodiment is a method for processing cheese, the method comprising providing cheese and warming the cheese to at least 130xc2x0 F. and stirring to form an aqueous phase from the cheese, and also forming a phase of butterfat, and a cheese product. The method then separates the butterfat phase, and also separates the aqueous phase. A cheese product remains, the cheese product having at least a portion of its fat removed, wherein the cheese product is selected from the group consisting of low fat cheese, light cheese, and reduced fat cheese.
Another embodiment of the invention is a cheese product, the cheese product having less fat than the starting cheese. The cheese is a low fat cheese, a light cheese, or a reduced-fat cheese product, made by this process. Cheese flavorings with lower levels of fat are also embodiments.
Another embodiment is a method for removing undesirable flavors in cheese. The method for extracting these undesirable flavors includes providing a cheese, the cheese containing fat and having an undesirable flavor. The method includes heating or warming the cheese to at least 130xc2x0 F., while stirring the cheese. Water is added to the cheese, and phase separation occurs to form an aqueous phase, a butterfat phase, and a cheese product phase. The butterfat phase and the aqueous phase may be separated by centrifuging. A cheese product remains, the cheese product having at least a portion of its fat removed and enough of the undesirable flavor removed so that the cheese has a consumer-acceptable flavor. For instance, a bitter flavor may be reduced by this method to a slight to very-slightly bitter flavor. The undesirable flavor components tend to be aqueous, and are thus removed from the cheese in the aqueous phase. The normally-present mesophilic bacteria are deactivated by the temperature used in fractionating the cheese. Further aspects of the invention will be apparent from the drawings and description of the preferred embodiments detailed below.